NuPAGE Bis-Tris Gels

NuPAGE Bis-Tris Gels are precast polyacrylamide gels designed to give optimal separation for a wide range of molecular weight proteins during gel electrophoresis. NuPAGE Bis-Tris Gels have a neutral pH environment that minimizes protein modifications, resulting in sharper bands without typical gel "smiling.” NuPAGE Bis-Tris Gels can be used for western blotting, sequencing, mass spectrometry, and any other application in which protein integrity is crucial.

Features of the NuPAGE Bis-Tris Gels include:

• Better protein integrity—optimized sample preparation process preserves your proteins
• Wide ranges of molecular weight separation—selecting the right gel and running buffer helps to achieve the optimal separation of your proteins
• Faster run times—separation of your proteins can be attained in as little as 35 minutes
• Longer shelf life— gels can be stored for at least 12 months at room temperature

NuPAGE Bis-Tris Gels are formulated for denaturing gel electrophoresis applications. For optimal sample preparation, we recommend using buffers containing SDS. The gels can be run using MES SDS running buffer to better resolve small proteins and MOPS SDS running buffer to resolve medium- to large-size proteins. 

NuPAGE Bis-Tris Gels use a bis-tris discontinuous buffer system involving three ions:

• Chloride (–) is from the gel buffer and serves as a leading ion due to its high affinity to the anode relative to other anions in the system. The gel buffer ions are bis-tris (+) and Cl (–) (pH 6.4).

• MES or MOPS (–) serves as the trailing ion in the running buffer. The running buffer ions are tris (+), MOPS/MES (–) and dodecylsuflate (pH 7.3–7.7).

Bis-tris (+) is the common ion present in the gel buffer and running buffer. The combination of lower pH gel buffer (pH 6.4) and the running buffer (pH 7.3–7.7) results in a significantly lower operating pH of 7 during electrophoresis.